The state of Arkansas plans to put to death eight inmates over a span of 10 days next month, a pace of executions unequaled in recent American history and brought about by a looming expiration date for a drug used by the state for lethal injections.

The eight men facing execution — four black and four white — are among 34 death row inmates in Arkansas, where capital punishment has been suspended since 2005 over legal challenges and difficulty in acquiring the drugs for lethal injections.

All eight men were convicted of murders that occurred between 1989 and 1999, and proponents of the death penalty and victims’ rights in the state have been frustrated that the cases have dragged on so long.

At a news conference this week, Gov. Asa Hutchinson, a Republican and former federal prosecutor, seemed to regret that the executions were so closely stacked.

“I would love to have those extended over a period of multiple months and years, but that’s not the circumstances that I find myself in,” said Mr. Hutchinson, who took office in 2015. “And, again, the families of the victims that have endured this for so many years deserve a conclusion to it.”

In a statement on Friday, Mr. Hutchinson said that it was necessary to schedule the executions close together because of doubts about the future availability of one of three drugs the state uses in its lethal-injection procedure. State officials have previously said that the expiration date would pass in April for Arkansas’s supply of midazolam, a drug that has been used in several botched and gruesome lethal injections in other states in recent years.

Amid the controversy generated by such cases, a number of pharmaceutical companies have restricted their drugs from use for capital punishment. Some states have had difficultly finding midazolam. Arizona announced last year it would stop using it in part because of the logistical challenges.

“It is uncertain as to whether another drug can be obtained,” Mr. Hutchinson said in the statement, “and the families of the victims do not need to live with continued uncertainty after decades of review.”

This week, the governor signed proclamations setting four execution dates for the eight inmates between April 17 and 27. Two men would be put to death on each of the four dates. If Arkansas follows that timetable, it will be at a rate unmatched by any state since the United States resumed the death penalty in 1977, according to the Death Penalty Information Center, a nonprofit research group that opposes capital punishment.

In 1997, Texas came close, putting eight inmates to death in May and again in June, but not over such a short number of days, the group said.

Critics of midazolam’s use in executions say it is a sedative, not an anesthetic, and is thus misapplied as a first round of lethal injection shots, with inmates sometimes able to feel pain from the subsequent lethal drugs that are administered. In one high-profile case in Oklahoma, a convict named Clayton D. Lockett, who was administered midazolam, died 43 minutes after the injections were started and appeared to struggle and moan.

The Arkansas Department of Correction has not refilled its stock of potassium chloride, the third and fatal drug administered in an execution, but a spokesman for Mr. Hutchinson said the governor had confidence the department would acquire it in time for the April executions.

Brian Stull, a senior staff attorney with the American Civil Liberties Union, argued that something was more likely to go wrong with so many executions scheduled so close together.

“Each of these prisoners is a person with rights that have to be honored, and each execution is a process that needs to be planned and handled with care and close attention to detail,” he said. “And that’s just impossible for Arkansas on this schedule. Because they’re trying to do too much, too quickly, with too little preparation. It’s likely to lead to botched executions.”

The lawyers for the condemned men say some legal avenues of appeal are still available. Their lengthy appeal process has included a petition asking the United States Supreme Court to review the matter. The court denied the petition on Feb. 21.

But the men’s lawyers said that even a best-case scenario would most likely only entail an alternative form of execution to the current three-drug injection method, which the lawyers argue is unconstitutionally cruel.

“The state’s supply of midazolam runs out on April 30,” said John Williams, an assistant federal public defender based in Little Rock. “And so the schedule is quite obviously dictated by that, and we think it is inhumane that the state would schedule executions so as to get rid of a drug supply that the evidence shows is cruel and unusual.”

The executions come at an unsettled and complicated moment for capital punishment in the United States.

Nationwide, the number of executions has been in steep decline, and though many Americans support the death penalty, some polling shows that support for capital punishment has been steadily waning since the mid-1990s. And while the Supreme Court has been less than clear on its collective stance toward capital punishment, President Trump is an ardent and longtime proponent. The president’s opinions may have little direct effect on state cases, but his blunt, tough-on-crime speech is sure to influence the tone of the national conversation.

In Arkansas, Mr. Hutchinson has earned a reputation as a relative moderate, serving in some cases as a break on the hard-right ambitions of the Republican-controlled legislature. But he has also been determined to reactivate the death penalty.

The year he took office, he scheduled the execution of eight inmates, including several of the same men set to die next month, saying that they had exhausted all appeals. But a state court halted the executions because of a lawsuit against the state over its provisions at the time that kept secret the sources of its lethal injection drugs. The state was then ordered to disclose information about its supply chain.

Mr. Hutchinson’s latest effort to restart executions came after the state’s attorney general, Leslie Rutledge, told him that the eight men had no additional legal challenges to their executions.

Mr. Ward went into a Jackpot convenience store in Little Rock on a night in August 1989 and asked the clerk, Rebecca Lynn Doss, an 18-year-old who read the Bible during the overnight shift by herself, for help unlocking the men’s restroom. Inside the bathroom, he sexually assaulted and strangled her. A police officer spotted him leaving the restroom and about to get on his motorcycle to leave.

Mr. Lee killed Debra Reese, 26, in her home in February 1993 in Jacksonville, Ark., outside Little Rock, after beating her 36 times with a tire tool that her husband had given her for protection while he was out of town.

Kenneth Williams killed a cheerleader at the University of Arkansas at Pine Bluff in December 1998 but escaped from a maximum-security prison after a jury sentenced him to life the next year. A few miles from the prison, he fatally shot Cecil Boren, a farmer who was working in the yard while his wife was at church, and stole his truck. Mr. Williams led the police into Missouri in a high-speed chase before he crashed into a car, killing the driver. In 2005, he confessed to killing a 36-year-old man the same day he shot the cheerleader.

At the news conference, Mr. Hutchinson said he had discussed concerns about stacking the executions, and its potential ill effects on prison employees, with Wendy Kelley, the state corrections director.

“The answer is it’s not any easier to string it over four or five months than to do it in a measured and separated fashion, but in the sequence we have outlined,” he said.

Correction:March 3, 2017

Because of an editing error, an earlier version of a picture caption with this article misidentified four Arkansas inmates scheduled to executed in April. At bottom from right, they are Stacey Johnson, Don Williamson Davis, Marcel Williams and Ledell Lee.

A version of this article appears in print on , on Page A1 of the New York edition with the headline: Arkansas Races to Execute 8 Men in 10 Days Before Drug Expires. Order Reprints | Today’s Paper | Subscribe